Creating a test class

Hey guys ... new here. I'm a freshman in college taking my first programming course, so bear with me as I ask some pretty simple questions.

Basically what I'm doing with this class is keep track of a date that inputted. It should handle everything correctly ... However, that's not the piece of code I have a question with (I'm just putting it in for you guys to refer to if you need it).

Java Code:

package calendar;
/**
* A "calendar" that keeps track of the date
*/
public class Date {
private int day;
private String month;
private int year;
/**
* Creates a instance of a date and starts it on November 2, 2010
*/
public Date() {
day = 2;
month = "November";
year = 2010;
}
/**
* Creates a date where the user specifies the date to start on.
* The month must contain a string with a valid month name.
* @ensure The day must contain an integer with values between 1-30 or 1-31 depending on the date.
* For example, if the month is January, the day must have a minimum value of 1 and a maximum value of 31.
* Note that February and leap year are exceptions.
* The year must be non negative.
* @param m A string that represents the month passed in.
* @param day An integer that represents the day passsed in
* @param year Also an integer that represents the year passed in - must be positive.
*/
public Date (String m, int day, int year) {
if (m.equals("January") || m.equals("February") || m.equals("March") || m.equals("April") || m.equals("May") || m.equals("June") || m.equals("July") || m.equals("August") || m.equals("September") || m.equals("October")
|| m.equals("November") || m.equals("December")) {
month = m;
}
this.day = day;
if (year > 0) {
this.year = year;
}
}
/**
* @ensure that the month, day, and year are all valid inputs.
* @return Date returns the current date in the form of a string
*/
public String getDate() {
return month + " " + day + "," + " " + year + ".";
}
/**
* @return day the day of the current date.
*/
public int getDay() {
return day;
}
/**
* @That the month is capitalized and spelled correctly.
* @return month the month of the current date.
*/
public String getMonth() {
return month;
}
/**
* @ensure year > 0
* @return year returns the year of the current date. The year must be a non-negative number.
*/
public int getYear() {
return year;
}
/**
* @require that the method performs the correct operations
* This method will run the tomorrow() method 7 times, which
* will automatically correct what happens when the date gets
* to the end of the month.
*/
public void nextWeek() {
for (int i = 0; i <7; i++) {
tomorrow();
}
}
/**
* This method assures that if the month is on a certain date and day,
* it will automatically kick down to the next correct month and day.
* Leap year is correctly handled by a couple else if statements saying
* that if the year divided by 4 it is a leap year. However, that is not
* the only exception - if the year divisible by 100 with a remainder of not
* 0 and if the year is divisble by 400 with no remainder then the year is
* also a leap year.
*/
public void tomorrow() {
if (month.equals("January") && day == 31) {
day = 1;
month = "February";
}
else if (month.equals("February") && year%4 != 0 && day == 28) {
day = 1;
month = "March";
}
else if (month.equals("February") && year%4 == 0 &&(year%100 != 0 || year%400 == 0) && day == 28) {
day = 29;
}
else if (month.equals("February") && day == 29) {
day = 1;
month = "March";
}
else if (month.equals("March") && day == 31) {
day = 1;
month = "April";
}
else if (month.equals("April") && day == 30) {
day = 1;
month = "May";
}
else if (month.equals("May") && day == 31) {
day = 1;
month = "June";
}
else if (month.equals("June") && day == 30) {
day = 1;
month = "July";
}
else if (month.equals("July") && day == 31) {
day = 1;
month = "August";
}
else if (month.equals("August") && day == 31) {
day = 1;
month = "September";
}
else if (month.equals("September") && day == 30) {
day = 1;
month = "October";
}
else if (month.equals("October") && day == 31) {
day =1;
month = "November";
}
else if (month.equals("November") && day == 31) {
day = 1;
month = "December";
}
else if (month.equals("December") && day == 31) {
day = 1;
month = "January";
year = year + 1;
}
else {
day = day + 1;
}
}
}

The next thing we were required to do is to create a test class to test everything ... This is what I have so far, however I'm not sure how to procede.

Thanks for the reply, Zack. I see what you're saying ... the example we had worked on in class somehow made sure that the method they were testing was functioning correctly.

I really don't know a lot about assertEquals (...) because our teacher basically showed us an example in class real quick ... I didn't have a great understanding of how they worked.

However, one of the requirements for this assignment is to create a test class that makes sure the nextWeek() and tomorrow() methods work. I decided to start with the nextWeek() method, but really didn't get anywhere - sorta just started throwing things together.

Alright, thanks - I see how that would work.
I emailed my professor to see how they would like me to correctly write this test class... here's the response

So if you wanted to check if a date was January 1, 2010, you would need three separate assert statements. The first would check the month by calling getMonth(), the second check the day with getDay() and the third getYear(), all on the same object.

I think I understand what she's getting at, but could anyone show me a simple example of how I would use all 3 assert statements to correctly check that?